Electronics Forum | Tue Aug 28 09:11:26 EDT 2012 | rway
Thank you for your reply. We will try your suggestions and keep you posted.
Electronics Forum | Mon Aug 27 13:02:32 EDT 2012 | rway
We will look at the oven speed. We considered stiffeners but opted against that due to the risk of moving parts pre-reflow due to handling. 90 deg? I don't know. This may or may not help with the bowing. Considering there is little to no substra
Electronics Forum | Mon Aug 27 11:11:16 EDT 2012 | rway
We have 1/2 dozens 0.031 pcbs that bow after going through the oven. We are looking for a solution to this problem to prevent bowing of the pcbs. As a result of the bowing, the pcbs, on occasion get caught in the oven, and more often have transfer
Electronics Forum | Mon Aug 27 12:51:32 EDT 2012 | cobham1
I have run 0.031 boards. One of the things you may want to look at is the speed of the oven. With 14 zones you may be going to slow with the board which could be the reason your boards are starting to bow. You might also think about adding stiffners
Electronics Forum | Mon Aug 27 16:40:15 EDT 2012 | cobham1
Ran them with stiffners and I worried about moving parts also but had the stiffners cut so that they could only go on so far which made it ok because The distance from the stiffners and parts was 1/16 of an inch no problem with movement.
Electronics Forum | Tue Aug 28 08:28:30 EDT 2012 | rgduval
We agree with all of the previous comments, and would add the following: Warpage is generally caused by excess moisture in the raw boards. Have you tried baking the boards prior to assembly? We had this issue on a simple 4-layer board, and found t
Electronics Forum | Mon Aug 27 11:51:47 EDT 2012 | cobham1
Its no my turn to give some advise. My first question would be can you put the boards into a carrier of some sort. There are many wonderful companies that make carriers that are ment for running down a smt line. This can be expensive unless you order
Electronics Forum | Mon Aug 27 12:31:04 EDT 2012 | rway
Its no my turn to give some advise. My first > question would be can you put the boards into a > carrier of some sort. There are many wonderful > companies that make carriers that are ment for > running down a smt line. This can be expensive > u
Electronics Forum | Fri Dec 27 16:26:30 EST 2013 | davef
I expect to find the specification and measurement method for the bow & twist of an assembly to be on the assembly drawing. Comments are: * Expecting that an industry committee to write a bow & twist spec for an assembly they know nothing about is n
Electronics Forum | Fri Sep 30 10:13:54 EDT 2005 | Cmiller
We are having a random problem with boards bowing significantly. Its a large through hole board with only one QFP on it. The bowing occurs during the SMT reflow. The only conclusion I can come to is a problem at the board house that made it. I just w
